Latest Information (as of May 8, 2006 - 16:00 EST)The Canadian Food Inspection Agency (CFIA) has tested 12 cattle potentially exposed to the same feed as the affected animal. All tests were negative.The remaining 11 cattle from the feed cohort are being evaluated for compensation purposes and will be tested shortly.The investigation of animals of interest has been concluded. This includes 146 cattle from the affected animal’s feed cohort and its two most recently born offspring.Of these groups, 74 cattle had previously died, 34 cattle were deemed untraceable due to lack of information, 23 live cattle were located and 15 cattle were exported to the United States. Thirty-four untraceable animals out of 146 is not an unusual rate for investigations of this type.The findings of the feed investigation are being reviewed and will be posted to the CFIA’s Web site in a final report.

"The U.S. Department of Agriculture continues to work closely with our counterparts in Canada on animal tracebacks in regards to their most recent case of BSE. Canada has informed us that 15 feed cohorts of the BSE-positive animal entered the United States. USDA has located one of these animals, and it will be euthanized and tested. The disposition of the remaining 14 animals is still being determined. "Experience worldwide has shown us that it is highly unusual to find BSE in more than one animal in a herd or in an affected animal's offspring. However, we will continue to work with Canada to locate as many animals of interest in this case as possible. It is important to remember that the United States maintains a series of interlocking safeguards which are what protect animal and public health. These safeguards include the removal of specified risk materials from the food supply and the Food and Drug Administration's 1997 ruminant-to-ruminant feed ban."

http://www.aphis.usda.gov/newsroom/content/2006/04/bsecan.shtml

May 2, 2006 Statement by USDA Chief Veterinary Officer John Clifford Regarding the Conclusion of the Epidemiological Investigation Into a Bovine Spongiform Encephalopathy (BSE)-Positive Cow Found in Alabama• Alabama BSE Investigation Final Epidemiology Report

.42 On 15 May Mr Bradley sent a minute to Dr Watson, Dr Shreeve, Dr Roberts, Mr Wells and Mr Mike Dawson noting that, 'by agreement with the Director', the proposed Vision article would now be circulated as a separate Directive to VICs in England and Wales only.

http://www.bseinquiry.gov.uk/files/yb/1987/05/15001001.pdf

IN CONFIDENCE

It has been agreed that a joint/co-ordinated CVL-VIS publication will be produced in due course. Meanwhile, because of the nature of the disorder, its political implications and possible effects on exports it is essential that VIS staff must not, at this stage, discuss it with or consult workers at Research Institutes and University Departments. Furthermore, any statements for publication or discussions at meetings must be cleared by the respective Directors of the Services.

http://www.bseinquiry.gov.uk/files/yb/1987/05/22002001.pdf

2.44 On 27 May Dr Peter Dawson succeeded Dr Williams as the ACVO and Head of the VI Service, and Dr Richard Cawthorne succeeded Dr Peter Dawson as Head of the Veterinary Investigation Section (VI Section) at Tolworth.

2.45 The final version of Mr Wells's article, entitled 'A Novel Bovine Neurological Disorder?', was eventually circulated on 8 June 1987 to Superintending Veterinary Investigation Officers in England and Wales. The document was headed 'urgent' and 'in confidence'. It described the nature, symptoms and pathology of the new disease and gave instructions for the submission of pathological material to the CVL. It included the following directions:

Similar clinical cases are of interest to VI Section, Tolworth, and the Pathology and Virology Departments at CVL. Such cases must be notified initially only to SVO(HQ), VI Section, Tolworth and Neuropathology Section, Pathology Department, CVO. At this stage VI staff should not consult workers at Research Institutes or University Departments . . . A co-ordinated VIS/CVL publication on this subject is proposed. All statements for publication, or discussion at meetings MUST BE CLEARED by respective Directors of Services.

http://www.bseinquiry.gov.uk/files/yb/1987/06/08001001.pdf

It is essential not to refer to the condition as bovine scrapie. While the clinical and pathological changes may provide evidence of its similarity to diseases caused by unconventional infectious agents such as scrapie in sheep, it is important to emphasise that the aetiological basis of BSE remains unknown and no connection with encephalopathies in other species, including scrapie in sheep, has been established.

http://www.bseinquiry.gov.uk/files/yb/1987/10/27003001.pdf

. . . the fact that it so far appears to be a uniquely British disorder could prejudice our cattle exports if it is publicised in inaccurate or exaggerated terms. It would be particularly misleading if it were to be described as 'scrapie in cattle'. Scrapie is a disease of sheep, the existence of which in British flocks is an impediment to our export trade, but although it is also an encephalopathy there is no evidence that BSE is attributable to the same cause as scrapie and it is important to distinguish between the two conditions . . .A point to emphasise, if you are pressed on numbers of cases, is that while it may be suspected in over 100 herds and distributed over a wide area, it has been confirmed in only 25 animals, out of a total UK cattle population of just over 12.5 million. Moreover, cases tend to be in individual animals rather than whole herds being affected. There is no evidence that it is transmissible to humans or that the meat or milk from animals with BSE are affected.

http://www.bseinquiry.gov.uk/files/yb/1987/10/30001001.pdf

12/10/76AGRICULTURAL RESEARCH COUNCILREPORT OF THE ADVISORY COMMITTE ON SCRAPIEOffice NoteCHAIRMAN: PROFESSOR PETER WILDY

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A The Present Position with respect to ScrapieA] The Problem

Scrapie is a natural disease of sheep and goats. It is a slowand inexorably progressive degenerative disorder of the nervous systemand it ia fatal. It is enzootic in the United Kingdom but not in allcountries.

The field problem has been reviewed by a MAFF working group(ARC 35/77). It is difficult to assess the incidence in Britain fora variety of reasons but the disease causes serious financial loss;it is estimated that it cost Swaledale breeders alone $l.7 M duringthe five years 1971-1975. A further inestimable loss arises from theclosure of certain export markets, in particular those of the UnitedStates, to British sheep.

It is clear that scrapie in sheep is important commercially andfor that reason alone effective measures to control it should bedevised as quickly as possible.

Recently the question has again been brought up as to whetherscrapie is transmissible to man. This has followed reports that thedisease has been transmitted to primates. One particularly luridspeculation (Gajdusek 1977) conjectures that the agents of scrapie,kuru, Creutzfeldt-Jakob disease and transmissible encephalopathy ofmink are varieties of a single "virus". The U.S. Department ofAgriculture concluded that it could "no longer justify or permitscrapie-blood line and scrapie-exposed sheep and goats to be processedfor human or animal food at slaughter or rendering plants" (ARC 84/77)"The problem is emphasised by the finding that some strains of scrapieproduce lesions identical to the once which characterise the humandementias"

Whether true or not. the hypothesis that these agents might betransmissible to man raises two considerations. First, the safetyof laboratory personnel requires prompt attention. Second, actionsuch as the "scorched meat" policy of USDA makes the solution of theacrapie problem urgent if the sheep industry is not to suffergrievously.

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76/10.12/4.6

http://www.bseinquiry.gov.uk/files/yb/1976/10/12004001.pdf

STRICTLY PRIVATE AND CONFIDENTIAL 25, AUGUST 1995

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To minimise the risk of farmers' claims for compensation from feed compounders.

To minimise the potential damage to compound feed markets through adverse publicity.

To maximise freedom of action for feed compounders, notably by maintaining the availability of meat and bone meal as a raw material in animal feeds, and ensuring time is available to make any changes which may be required.

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THE FUTURE

4..........

MAFF remains under pressure in Brussels and is not skilled at handling potentially explosive issues.

5. Tests _may_ show that ruminant feeds have been sold which contain illegal traces of ruminant protein. More likely, a few positive test results will turn up but proof that a particular feed mill knowingly supplied it to a particular farm will be difficult if not impossible.

6. The threat remains real and it will be some years before feed compounders are free of it. The longer we can avoid any direct linkage between feed milling _practices_ and actual BSE cases, the more likely it is that serious damage can be avoided. ...

SEE full text ;

http://www.bseinquiry.gov.uk/files/yb/1995/08/24002001.pdf

Like lambs to the slaughter31 March 2001Debora MacKenzieMagazine issue 2284What if you can catch old-fashioned CJD by eating meat from a sheep infectedwith scrapie?FOUR years ago, Terry Singeltary watched his mother die horribly from adegenerative brain disease. Doctors told him it was Alzheimer's, butSingeltary was suspicious. The diagnosis didn't fit her violent symptoms,and he demanded an autopsy. It showed she had died of sporadicCreutzfeldt-Jakob disease.

Most doctors believe that sCJD is caused by a prion protein deforming bychance into a killer. But Singeltary thinks otherwise. He is one of a numberof campaigners who say that some sCJD, like the variant CJD related to BSE,is caused by eating meat from infected animals. Their suspicions havefocused on sheep carrying scrapie, a BSE-like disease that is widespread inflocks across Europe and North America.

Now scientists in France have stumbled across new evidence that adds weightto the campaigners' fears. To their complete surprise, the researchers foundthat one strain of scrapie causes the same brain damage in ...

Edited by D. Carleton Gajdusek, Centre National de la RechercheScientifique, Gif-sur-Yvette, France, and approved December 7, 2000(received for review October 16, 2000)

Abstract

There is substantial scientific evidence to support the notion that bovinespongiform encephalopathy (BSE) has contaminated human beings, causingvariant Creutzfeldt-Jakob disease (vCJD). This disease has raised concernsabout the possibility of an iatrogenic secondary transmission to humans,because the biological properties of the primate-adapted BSE agent areunknown. We show that (i) BSE can be transmitted from primate to primate byintravenous route in 25 months, and (ii) an iatrogenic transmission of vCJDto humans could be readily recognized pathologically, whether it occurs bythe central or peripheral route. Strain typing in mice demonstrates that theBSE agent adapts to macaques in the same way as it does to humans andconfirms that the BSE agent is responsible for vCJD not only in the UnitedKingdom but also in France. The agent responsible for French iatrogenicgrowth hormone-linked CJD taken as a control is very different from vCJD butis similar to that found in one case of sporadic CJD and one sheep scrapieisolate. These data will be key in identifying the origin of human cases ofprion disease, including accidental vCJD transmission, and could providebases for vCJD risk assessment.

http://www.pnas.org/cgi/content/full/041490898v1

60. ARC funding of scrapie research was never adequate but at least it was appropriately

long-term. As a result of the USA Department of Agriculture’s scrapie eradication

programme, both MRI and IRAD received 5-10 year grants for sheep experiments under

US Public Law 480. This was an Act ‘to increase the consumption of US agricultural

commodities in foreign countries, to improve the foreign relations of the US, and for other

purposes’. At IRAD, at this time, it had become the practice to economise by taking

lamb crops from the scrapie-injected ewes, for sale locally for human consumption.

''this was a fanatical incident to be _avoided_ in the US _at all costs_''...

Gerald Wells: Report of the Visit to USA, April-May 1989

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The general opinion of those present was that BSE, as anovert disease phenomenon, _could exist in the USA, but if it did,it was very rare. The need for improved and specific surveillancemethods to detect it as recognised...

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It is clear that USDA have little information and _no_ regulatoryresponsibility for rendering plants in the US...

snip...

3. Prof. A. Robertson gave a brief account of BSE. The US approachwas to accord it a _very low profile indeed_. Dr. A Thiermann showedthe picture in the ''Independent'' with cattle being incinerated and thoughtthis was a fanatical incident to be _avoided_ in the US _at all costs_...

snip...

http://www.bseinquiry.gov.uk/files/mb/m11b/tab01.pdf

To be published in the Proceedings of theFourth International Scientific Congress inFur Animal Production. Toronto, Canada,August 21-28, 1988

ABSTRACTEpidemiologic investigation of a new incidence oftransmissible mink encephalopathy (TME) in Stetsonville, Wisconsinsuggests that the disease may have resulted from feeding infectedcattle to mink. This observation is supported by the transmission ofa TME-like disease to experimentally inoculated cattle, and by therecent report of a new bovine spongiform encephalopathy inEngland.

INTRODUCTION

Transmissible mink encephalopathy (TME) was first reported in 1965 byHartsoughand Burger who demonstrated that the disease was transmissible with a longincubationperiod, and that affected mink had a spongiform encephalopathy similar tothat found inscrapie-affecied sheep (Hartsough and Burger, 1965; Burger and Hartsough,1965).Because of the similarity between TME and scrapie, and the subsequentfinding that thetwo transmissible agents were indistinguishable (Marsh and Hanson, 1969), itwasconcluded that TME most likely resulted from feeding mink scrapie-infeciedsheep.The experimental transmission of sheep scrapie to mink (Hanson et al., 1971)confirmed the close association of TME and scrapie, but at the same timeprovidedevidence that they may be different. Epidemiologic studies on previousincidences ofTME indicated that the incubation periods in field cases were between sixmonths andone year in length (Harxsough and Burger, 1965). Experimentally, scrapiecould not betransmitted to mink in less than one year.To investigate the possibility that TME may be caused by a (particularstrain ofscrapie which might be highly pathogenic for mink, 21 different strains ofthe scrapieagent, including their sheep or goat sources, were inoculated into a totalof 61 mink.Only one mink developed a progressive neurologic disease after an incubationperiod of22 mon..s (Marsh and Hanson, 1979). These results indicated that TME waseither causedby a strain of sheep scrapie not yet tested, or was due to exposure to ascrapie-like agentfrom an unidentified source.

OBSERVATIONS AND RESULTS

A New Incidence of TME. In April of 1985, a mink rancher in Stetsonville,Wisconsinreported that many of his mink were "acting funny", and some had died. Atthis time, wevisited the farm and found that approximately 10% of all adult mink wereshowingtypical signs of TME: insidious onset characterized by subtle behavioralchanges, loss ofnormal habits of cleanliness, deposition of droppings throughout the penrather than in asingle area, hyperexcitability, difficulty in chewing and swallowing, andtails arched overtheir _backs like squirrels. These signs were followed by progressivedeterioration ofneurologic function beginning with locomoior incoordination, long periods ofsomnolencein which the affected mink would stand motionless with its head in thecorner of thecage, complete debilitation, and death. Over the next 8-10 weeks,approximately 40% ofall the adult mink on the farm died from TME.Since previous incidences of TME were associated with common or sharedfeedingpractices, we obtained a careful history of feed ingredients used over thepast 12-18months. The rancher was a "dead stock" feeder using mostly (>95%) downer ordead dairycattle and a few horses. Sheep had never been fed.

Experimental Transmission. The clinical diagnosis of TME was confirmed byhistopaihologic examination and by experimental transmission to mink afterincubationperiods of four months. To investigate the possible involvement of cattle inthis diseasecycle, two six-week old castrated Holstein bull calves were inoculatedintracerebrallywith a brain suspension from affected mink. Each developed a fatalspongiformencephalopathy after incubation periods of 18 and 19 months.

DISCUSSIONThese findings suggest that TME may result from feeding mink infected cattleandwe have alerted bovine practitioners that there may exist an as yetunrecognizedscrapie-like disease of cattle in the United States (Marsh and Hartsough,1986). A newbovine spongiform encephalopathy has recently been reported in England(Wells et al.,1987), and investigators are presently studying its transmissibility andpossiblerelationship to scrapie. Because this new bovine disease in England ischaracterized bybehavioral changes, hyperexcitability, and agressiveness, it is very likelyit would beconfused with rabies in the United Stales and not be diagnosed. Presently,brains fromcattle in the United States which are suspected of rabies infection are onlytested withanti-rabies virus antibody and are not examined histopathologically forlesions ofspongiform encephalopathy.We are presently pursuing additional studies to further examine the possibleinvolvement of cattle in the epidemiology of TME. One of these is thebackpassage ofour experimental bovine encephalopathy to mink. Because (here are as yet noagent-specific proteins or nucleic acids identified for these transmissibleneuropathogens, onemeans of distinguishing them is by animal passage and selection of thebiotype whichgrows best in a particular host. This procedure has been used to separatehamster-adapted and mink-udapted TME agents (Marsh and Hanson, 1979). Theintracerebralbackpassage of the experimental bovine agent resulted in incubations of onlyfour monthsindicating no de-adaptation of the Stetsonville agent for mink after bovinepassage.Mink fed infected bovine brain remain normal after six months. It will beessential todemonstrate oral transmission fiom bovine to mink it this proposedepidemiologicassociation is to be confirmed.

ACKNOWLEDGEMENTSThese studies were supported by the College of Agricultural and LifeSciences,University of Wisconsin-Madison and by a grant (85-CRCR-1-1812) from theUnitedStates Department of Agriculture. The authors also wish to acknowledge thehelp andencouragement of Robert Hanson who died during the course of theseinvestigations.